Project Fi in Vancouver and Alaska

While on vacation I got a chance to test Project Fi coverage in Vancouver and Alaska (including Juneau, Ketchikan, Skagway, and Hoonah). In Vancouver coverage was great; I reliably had a solid LTE signal. And it was great to be able to draw on the Internet without having to pay extra for international access.
Coverage in Alaska, was pretty spotty. Fi is an overlay on top of Sprint, T-Mobile, and US Cellular, and apparently they don’t cover Alaska very well. I could occasionally get an LTE signal in the middle of town, but much of the time I was lucky to get a 3G signal (in fact, most of the time I could only get a voice signal, not a data one). By contrast, my wife could usually get a pretty solid AT&T LTE signal (although it often seemed to be bandwidth saturated, likely overwhelmed by cruise ship passengers frantically posting photos on social networks).
Verdict so far: if you do travel internationally, Project Fi is awesome. If you plan to move to Alaska, you should probably go with AT&T.